If you're having a player generate a prisoner character, I am assuming you want to actually play out prison things.
I think the first choice you need to make as a GM is how you intend to have the players get out of prison:
Do you intend to have the players:
1) ... break out of the prison and escape as fugitives ("prison break")?
2) ... have the players freed on some context by the authorities, possibly to do something dangerous ("the Dirty Dozen" or "the Fast and Furious")?
3) ... serve out their time and being freed? I'm not sure this is really a good option -- piracy and murder are pretty serious so they'd be in prison for a long time if not forever. It wouldn't be done in two sessions in any case and not very interesting for a tabletop game in any case (it might be interesting as a single-player game).
The most difficult part about playing out prison scenarios is the escape. The point of a prison world is to hold various criminals (potentially political prisoners) far from civilization where they can't spread their views or prey on people -- these are people governments do not want to simply casually allow back into society. At the same time, that means players are going to find it very difficult to escape and the methods that exist tend to end up deus ex machina (eg; events that would essentially happen regardless of what the players do).
Unfortunately, piracy and murder makes the character the "scum and villany" in Mos Eisley (unless he had some sort extenuating circumstance, which I kinda doubt). I'm surprised he wasn't spaced as well. Regardless, given he's scum and villainy my ideas would be make him muck around in that.
For example, when I was designing a prison planet, I had a few ideas, ranging in what I wanted to do. I settled on this:
A prison "planet" that is actually a bunch of hulks in orbit around a world, with stripped down hulks being removed to melt down the remains and new ones arriving. The prisoners serve as shipbreakers - removing fittings from the hulks like toilets, desks, light fixtures, plumbing, wiring, and so on. The gutted hulks that remain are then towed off to be melted down and recycled. This kind of work isn't very profitable - only by using prison labor does it generate a small profit. The really profitable parts - such as the Jump Drive, fusion reactor, large battery arrays, ship's computer, and life support and other major systems have already been removed by civilian contractors beforehand; only after these valuable parts that could be used to make a true starship are removed are the hulks handed over to the prison cluster. This is also why civilian shipbreakers don't complain about prisoners doing this - they've already removed anything with good resale value.
Working conditions are pretty bad - a lot of the hulks are radioactive, there's old batteries that might explode, and so on. Oh, the local star (whose life zone they're in) also flares a some days out of every month, showering the hulks in deadly radiation - everyone has to be in a hulk or space station or die. The ships are lashed to each other using cables but it's still about 100 meters between each ship - prisoners are not expected to move from hulk to hulk, but some do by shimmying along the cables or other methods. Obviously, the danger of "falling" into space and very slowly cooking to death in the Life Zone's strong sunlight is terrifying and most prisoners usually "secure" an emergency EVA unit. This doesn't even get into the prison gang wars. The prison works as the administrators control the oxygen, food/water, battery recharges, and lodging for most of the part. Prisoners work a week in the ships - sleeping in their spacesuits, sipping food liquids, and so on, getting resupplies every day from an old beaten-up in-system tug that stops by every hulk for about 30 minutes whereupon prisoners trade their output for resupply.
The most productive gang in a week is given the weekend off - they get to go to the dorm starship, take off their spacesuit, watch vids, and so on. The others only get this privilege once a month. Prisoners have a very basic set of things they're supposed to have - anything beyond this is confiscated by the prison authority; a basic spacesuit and work tools (hand tools - such as drills, electric saws, crowbars, screwdrivers, and so on). This opportunity is also used to check the health of prisoners and ill prisoners are given medical treatment; this meets the bare requirements of the prison's responsibilities to prisoner welfare. Only the most vile criminals and dangerous political prisoners are sent here, so it's basically a death sentence without actual execution by the state. The Imperium sends people here ... and many planetary governments pay the Imperium to take their worst off to here as well.
The basic social unit of the prison is the "work gang" - a group of 8 to 12 inmates who are moved as a unit to work sites and their productivity is added up to determine if they get perks or not. Over time, this has led to alliances of gangs, gang overlords, and so on. Small, weak, or new gangs are regularly leaned on. Most work gangs "pay" a certain amount of their salvage to more powerful gang alliances for "protection" or owe fealty to larger gangs to protect their own salvage from being taken. Some work gangs get their salvage taken entirely, don't get resupplied and die for want of oxygen or water. Similarly, new prisoners have to "prove" themselves as well or risk being shanked for their spacesuit and so on. New prisoners (such as the players) will be "processed" - new prisoners with the proper Zero-G skills might simply be organized into a new gang. Otherwise, a gang that has taken ... losses ... will conveniently pick up all the players to replace their losses.
As you can see, because the prison authority controls the essentials, it is pretty loosely run - they don't even keep track of prisoner rolls but they do keep strict control over what ships jump in - ships that jump in which don't identify themselves get destroyed. Beyond this, provided not too many prisoners die and productivity is kept to a certain level, the Wardens leave the prisoners alone, leading to alliances of gangs of workers controlling what really goes on among the hulks. Over time, prisoners have salvaged sufficient parts to make their own solar power to run atmosphere recycling, hydroponic gardens, and so on, but these operations are small - most that are detected by the wardens are shut down (not by Marines but simply by fire from the prison authority ships after a warning of those aboard to leave), so any "independent" operations are always small and not in the position to allow the prisoner population at large to be independent of the authority. Nevertheless these "indie" operations remain critical to the running of the prison - tiny prisoner-merchant lords do things like secure an inmate's possessions while he's in the dorm ships (otherwise, they'd just get their basic spacesuit when they leave with anything else being confiscated), trade vaulables for other things so on. As might be expected the "lords" of the gang faction system basically do no work and kick back in their "palaces", giving orders to their lieutenants.
The typical long-term prisoner will have a weapon, hazardous environment spacesuit, extra oxygen bottles, an EVA thruster, a portable music player, and some jewelry (people are always forgetting things like rings or necklaces in ships and these are found and kept by prisoners) - work gangs might have an inflatable oxygen shelter secreted away (always good for stretching the legs outside of the suit, if only for a few hours), old rations to break the monotony of the liquid diet, cigarettes, booze, and so on. While some of these items are fabricated in an ad-hoc fashion, mostly prisoners find stuff while they're salvaging and keep a few things for themselves; while a prisoner is initially given a TL9 spacesuit, if he finds a environment spacesuit secreted away somewhere, he'll likely have it inspected at a "business" (the inspection paid for with a gold ring a work gang-mate found under a mattress, for instance) to see if it is good, trade in his old spacesuit to the "business" and walk out wearing his new H-E suit. Meanwhile the "merchant" might rig up hammered sheet-metal or something to make the basic prisoner suit a bit more durable to trade to a newbie.
The escape opportunity exists in the form of a potentially jump-capable starship among the hulks. It starts with the discovery of a jump coil hidden in the hull plates of a starship being turned into scrap. ("What the heck is a Jump-5 crystal coil doing in a ship like that?" "It was a tramp freighter, those coils are primitive, probably from the first generation of J-5 battleships so its really heavy and it's damaged - merchant probably got it, decided he wanted a J-5 merchantman, found a powerful fusion reactor from somewhere and tried to do the work himself to make a "sleeper" ship. It probably fell over while they were trying to install it and they just shrugged their shoulders and decided to just put hull plates over it because it'd be too much work to remove it - if they had the reactor for J-5 jumps it'd be more than enough power to lift 60 more tons of mass" "So it works at Jump-5?" "No, it's cracked. We could probably repair it enough to work for one Jump-2 though...").
The jump coil is the breakthrough. The rest the players will have to negotiate and fight for:
* An Engineer and a few assistants to repair and install the Jump Coil if the players can't do it themselves.
* An empty hulk of appropriate size (this should be fairly easy).
* A Manuver Drive. The artificial gravity system of any starship can actually be used to create a low power M-Drive, provided it's reasonably close to a planet. An engineer will be required to do this work.
* A power supply. Prisoners find high capacity power cells and power conditioners all the time. The ship will need about 30 displacement tons of cells for a Jump-1. A power supply is more problematic. Traveller ships typically require a fusion reactor for a drive. You can't really power a Jump off of a battery. However, it's possible to make a Explosive Power Generator (EPG) from a thermonuclear warhead - which work crews find every few years on some odd hulk or another. There's probably a few floating around the work camp somewhere. Then an engineer will be needed to convert it into an EPG. (The EPG would be detonated outside of starship, irradiating the hull.)
* A navigation computer and a navigator. Navigation computers/star charts exist in the prison cluster in the hands of prisoners. But they'll need a navigator. If a PC is a navigator all the more reason.
* A place to work on their jury-rigged ship which won't be attacked/seized by the Gang Lords or discovered by the Authority. This will require delicate negotiation. Obviously, most Gang Lords are interested in leaving the system, but even the most ruthless and powerful Gang Lord will have to fear for his life when those who don't get a ticket out find out what's going on. Obviously the players will have to fear betrayal too.
A few thoughts: If your players don't have the requisite skills (Engineer, Astrogation, Computer, or Piloting) they'll have to find people who do. If you don't have much time to play out the entire assembly, it'll be a plus if your character(s) has at least one of skills; you can simply say one of the Gang Lords already has a ship mostly set up, he just needs some help to finish the last parts, using the skills the players have (be careful of betrayal of course - the Gang Lord might leave them behind or kill them en route or a lieutenant who gets bumped so the PCs and go is obviously not going to be too happy if he's promised that he'll be the new Gang Lord after the escape). If your players have none of these essential ship skills chances are they are probably are a team of stone cold killers (funny how Traveller works like that) ... and Gang Lords can always use some sicarios to secure the last components in return for a trip out...
